Systemics- spraying vs soaking - Orchid Board

Izzie · #1 10-02-2010, 01:21 PM

I seem to remember than some orchids (phals?) do not absorb much water through their foliage except at night and such. Correct?
That in mind, is just spraying with a systemic as effective as soaking the plant/roots?
Spraying is certainly more convenient.
I'm talking about a systemic like Bayer 3-in-1, particularly for use on plants coming in from being outside. (they will be repotted before coming inside)

King_of_orchid_growing:) · #2 10-02-2010, 04:30 PM

If Phals use CAM photorespiration, then yeah, the stomata are open only at night.

Stomata are located on the undersides of the leaves.

Or try using the medication in the water when you water the plants. The roots will absorb the water with the meds.

Although, if you're using it for insects, surface spray should be fine.

Orchid126 · #3 10-02-2010, 07:09 PM

The recommendation is to apply the product on the leaves, both sides, to run-off. And drenching the medium is also good, because eggs and larvae lurk there and the Bayer, while a systemic, is also a contact killer.

If you don't want to use the Bayer for the medium, then a solution of one tablespoon to a gallon of some soapy water like dish liquid, Murphy's Oil Soap, or Dr. Bronners Peppermint soap would be good. But by all means, treat the medium too.

Ray · #4 10-04-2010, 04:25 PM

Personally, I think a total-plant dunk is the way to go, and add a very small amount of wetting agent (such as liquid soap) to the solution to help wetting and penetrating.

The contact with any external baddy will be fatal, and the plant will primarily absorb the toxin for systemic use through its roots.

Izzie · #5 10-04-2010, 04:53 PM

Thanks for the replies guys. Especially orchid126! I have spent hours searching for a consistent ratio of soap: water for insecticidal soap, and have never found one that was "for sure".
I'll let you know how it goes.

Izzie · #6 10-04-2010, 04:53 PM

Right now, I'm most concerned about getting rid of the @#$%@^# gnats. Which needs to be done on the terrestrial houseplants as well, and I have NO idea where to go with that....

Ray · #7 10-05-2010, 08:41 AM

Soap: There is no "ideal" amount. There is, however, a minimum, and that is whatever it takes to break down the surface tension. I typically go for a teaspoon per gallon, which is probably overkill, but it's easy to estimate with a simple squirt from the bottle.

If you have fungus gnats, you have decomposing organic matter in your pots. Any insecticide will be effective at killing them - many folks use Bacillus thuringiensis v. israelensis (BT - in mosquito dunks) - and that's fine for the houseplants, but their mere presence in the orchids tells me you need to repot them. Killing the gnats is like killing the canary in the mine - the problem still exists.

bullsie · #8 10-05-2010, 09:28 AM

I prefer to drench my plants because for me, its the easiest and safest.

But I am a little concerned about the thoughts of dunking them. It seems a good method. But, it also would be in the safety of the plant if the water were changed after each dunking. Now that to me seems like more work and certainly more expense.

But maybe what I should ask is how is the dunking done - besides setting plant and pot into fluid. Do you change after each plant, disinfecting as you go? Or do you dunk one after another in the contents, ensuring complete destruction of bugs but possibly aiding virus transmission?

Izzie · #9 10-05-2010, 02:14 PM

Quote:

Originally Posted by Ray

Soap: There is no "ideal" amount. There is, however, a minimum, and that is whatever it takes to break down the surface tension. I typically go for a teaspoon per gallon, which is probably overkill, but it's easy to estimate with a simple squirt from the bottle.

If you have fungus gnats, you have decomposing organic matter in your pots. Any insecticide will be effective at killing them - many folks use Bacillus thuringiensis v. israelensis (BT - in mosquito dunks) - and that's fine for the houseplants, but their mere presence in the orchids tells me you need to repot them. Killing the gnats is like killing the canary in the mine - the problem still exists.

The two outside will be repotted before they come in, for sure.
I never thought to use the BT on the houseplants, I'll have to look into that. Thanks Ray!